About
RGraph is a JavaScript charts library based on
HTML5 SVG and canvas. RGraph is mature (over 15 years
old) and has a wealth of features making it an ideal
choice to show charts on your website.
License
RGraph can be used for free under the GPL or if
that doesn't suit your situation there's an
inexpensive (£99) commercial license available.
Download
Get the latest version of RGraph (version 6.17) from
the download page. There's also older versions available,
minified files and links to cdnjs.com hosted libraries.
The fillRect function
The fillRect
function is used for drawing rectangles on your canvas
. As the name would suggest it does not stroke them (ie it doesn't draw the outline) - only
drawing the filled rectangle. An important thing to remember is that it's not a path function - so you don't have to call the
fill
function - when you call the fillRect
function it immediately draws a filled rectangle on your canvas
. It uses the fillStyle
setting for the color to use.
Arguments to the function
- The X coordinate
- The Y coordinate
- The width of the rectangle
- The height of the rectangle
An example
<script> window.onload = function () { var canvas = document.getElementById("cvs"); var context = canvas.getContext('2d'); var x = 50; var y = 50; var width = 100; var height = 100; context.fillStyle = 'red'; context.fillRect(x, y, width, height); } </script>